Printing apparatus with means for indicating the selected printing pitch and paper advancing pitch

Abstract

A printing apparatus includes a power supply for supplying power thereto and a battery supply for supplying back-up battery power. A printing mechanism effects printing on a printing paper in accordance with one of a plurality of printing pitches, and a processor controls the printer and produces data signals. A selector selects one of a plurality of printing pitches and applies a signal indicating the selected printing pitch to the processor. A plurality of indicators each indicates a respective one of the plurality of printing pitches and one of the indicators is energized by a data signal produced by the processor. A memory is supplied with back-up battery power by the battery power supply and stores a selected one of the plurality of printing pitches. The memory is accessed by the processor. Further, the processor is responsive to the signal applied by the selecting means and indicative of the printing pitch to provide an energization data signal to the one of the indicators corresponding to the selected printing pitch. The processor is also responsive to initiation of supply of power from the power supply means to read out the selected printing pitch from the memory to provide the energization data signal to the one of the indicators corresponding to that printing pitch read from the memory.

We claim: 
     
       1. A printing apparatus comprising: power supply means for supplying power to said apparatus;   battery power supply means for supplying back-up battery power;   means for effecting printing on a printing paper in accordance with one of a plurality of printing pitches;   processor means for controlling said printing effecting means and for producing data signals;   an address bus connected to said processor means;   latchless key means for selecting one of said plurality of printing pitches and for transiently applying a pitch signal indicating the selected printing pitch to said processor means;   a plurality of indicating means each for indicating a respective one of said plurality of printing pitches, one of said indicating means being energized by a data signal produced by said processor means; and   memory means supplied with back-up battery power by said battery power supply means and, in response to said pitch signal, for storing the selected one of said plurality of printing pitches, said memory means being accessed by said processor means through said address bus;   said processor means being responsive to the pitch signal applied by said key means and indicative of said selected printing pitch to provide the energization data signal to said one of said indicating means corresponding to the selected printing pitch and also being responsive to initiation of supply of power from said power supply means to read out the selected printing pitch from said memory means to provide the energization data signal to said one of said indicating means corresponding to the selected printing pitch read from said memory means.   
     
     
       2. A printing apparatus according to claim 1, wherein said latchless key means comprises manually settable selecting means including a single key, operable on depression to cause said plurality of indicating means to indicate sequentially said plurality of printing pitches and to assume an initial state after a predetermined number of operations of said key.